A unitized load is a single large article or a plurality of articles grouped together for shipping. The articles may be individual items such as material bales. The article also may be containers filled with their own goods. Although the articles are usually the same, the articles may be a mixture of different things. The articles may be grouped orderly or randomly. The articles may be grouped on a wooden pallet, a non-wooden pallet, a slip sheet, a slip tray, or another shipping aid. Examples of these are described in U.S. Pat. Nos. 5,613,447, 5,881,651, and 6,490,982. Each unitized load may be stretch wrapped after it is formed. Unitized loads may be stacked one on top of the other when they are loaded into a container for shipping. When the shipper intends to stack the unitized loads, the shipper does not want to place the upper load on a thick pallet in order to save the air space that would have been occupied by the pallet. The shipper may use a thin slip sheet or a slip tray. Such unitized loads are placed directly on top of the other load. One problem with this stacking configuration is the problem of removing the top load from the bottom load after the top load settles into the top of the bottom load during transport. The loads are typically removed from the container with a power lift vehicle such as a fork lift. Inserting the forks between the upper and lower unitized loads can damage the stretch wrapping, the article packaging, or the articles themselves. When the articles are soft or flexible in nature, the process of inserting the forks between the unitized loads is more difficult and damage to at least the stretch wrap or protective packaging frequently occurs.
An example relevant to the invention is a unitized load of natural rubber bales. Each natural rubber bale is wrapped with a protective packaging layer and the entire unitized load of natural rubber bales is stretch wrapped for shipping. When one load is stacked on top of another, the natural properties of the rubber bales cause the loads to interlock together and bow outwardly. Inserting forks between these interlocked loads is not easy without damaging some portion of the load. Shippers thus desire a device and packaging configuration that solves the problem of inserting the forks between stacked upper and lower unitized loads, especially when the articles are soft or flexible.
Commercial rubber users prefer the rubber to be in bales of a convenient size, which is from about seventy to about eighty pounds, although the size of the bales varies greatly, depending on the producer and consumer. Such a size can be achieved using a bale having in the range of about 1.5 to 1.8 cubic feet of volume. The process of forming such a rectangular solid bale from the rubber is well known and will be well within the knowledge of one of skill in the rubber industry. Once formed, the bales are usually packaged in a plastic bag, although it is also known in the industry to package the bales in a shrink-wrap or stretch-wrap polymer, such as a polyethylene film. If for no other reason, this individual bale packaging minimizes the fusing of rubber in adjacent bales. Although these packaging techniques maintain the independence of the bales, the weight of the bales and the shipping time causes them to settle with the some bales to bulge outwardly. The bulging bales make the process of inserting forks of a forklift difficult.